<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript">
        function disp_prompt() {
            var name = prompt("请输入您的名字", "Bill Gates")
            if (name != null && name != "") {
                document.write("你好！" + name + " 今天过得怎么样？")
            }
        }
    </script>
</head>
<body>

<input type="button" onclick="disp_prompt()" value="显示提示框"/>

</body>
</html>

</body>
</html>